Silver halide emulsions which contain color couplers

ABSTRACT

The sensitivity of a light-sensitive photographic material containing in the silver halide emulsion layer a color coupler capable of forming a dye upon reaction with the oxidation product of a color-forming developer is increased by addition of a watersoluble quaternisation product of an Alpha , omega -bis(thiomorpholinyl)-alkane with a bifunctional polyalkylene oxide.

United States Patent Inventors Harald Huckstadt Cologne, Stammheim; Erwin Ranz, Leverkusen; Herbert Grabhofer, Cologne, Flittard, all of Germany Appl. No. 852,073

Filed Aug. 21, 1969 Patented Oct. 26, 1971 Assignee AGFA-Gevaert Aktiengesellschaft Leverkusen, Germany Priority Sept. 6, 1968 Germany P 17 97 263.3

SILVER HALIDE EMULSIONS WHICH CONTAIN COLOR COUPLERS 10 Claims, No Drawings U.S. Cl 96/55, 96/100, 96/107, 96/114 Int. Cl G03c 7/00,

[50] Field of Search 96/55, 100, 107

[56] References Cited UNITED STATES PATENTS 2,944,900 7/1960 Carroll et a1 96/100 3,370,048 2/1968 Reynolds 96/107 3,471,296 10/1969 Huckstadt et a1 .1 96/107 Primary Examiner-J. Travis Brown Attorney-Connolly and Hutz ABSTRACT: The sensitivity of a light-sensitive photographic material containing in the silver halide emulsion layer a color coupler capable of forming a dye upon reaction with the oxidation product of a color-forming developer is increased by addition of a water-soluble quaternisation product of an 01,0)- bis-(thiomorpholinyl)-alkane with a bifunctional polyalkylene oxide.

SILVER HALIDE EMULSIONS WHICH CONTAIN COLOR COUPLERS The invention relates to a process for increasing the sensitivity of photographic silver halide emulsions which contain color couplers as well as to color photographic silver halide emulsions with improved sensitivity.

It is known that the sensitivity of photographic silver halide emulsions can be increased by the addition of so-called development accelerators or chemical sensitizers Polyalkylene oxides and their derivatives have, inter alia, been described for this purpose. It is also known that in addition to simple polyalkylene oxides of different chain lengths, polyalkylene oxides with onium substituents may be used as chemical sensitizers.

Most of these compounds, however, have the disadvantage that in addition to increasing the sensitivity, they increase the fog of the emulsion. In many cases, these two factors are very adversely related to each other. This applies particularly to silver halide emulsions which contain color couplers. such emulsions being particularly liable to fogging.

Furthermore, it is known to use water-soluble quaternization products of tertiary polyamines with bifunctional polyalkylene oxide derivatives which contain open chain dial kylamines as chemical sensitizers for silver halide emulsions. The effectiveness of these compounds in color emulsions, however, is unsatisfactory.

It is among the object of the invention to provide chemical sensitizers for silver halide emulsions which contain color couplers which, while greatly increasing the sensitivity without concomitant increase of fogging.

We now have found that water-soluble quaternization products of a, w-bis-(thiomorpholinyl)-alkanes with bifunctional polyalkylene oxide derivatives are excellently suitable for use as development accelerators or chemical sensitizers for silver halide emulsions which contain color couplers.

The compounds have the following general formula:

VI LL wherein represents a 2 to 6,

n 3 to 300,

y 2 to 10, preferably 2 to 5, x any anion, e.g. halide, perchlorate, benzene sulfonate or the like.

Particular utility is exhibited by the following compounds:

III

VIII

cHz i The molecular weights given must be regarded as average values owing to the comparative inaccuracy of the methods of determination.

The substances according to the invention are prepared by quaternizing a bis-(thiomorpholinyl)-alkane, for example with the bis-tosylate of a polyalkylene oxide of desired chain length. The-method of preparation will be described in the following with reference to compound 1]:

STAGE 1 Fifty-one g. of thiomorpholine and g. of sodium hydroxide are dissolved in 75 ml. of water. 47 of ethylene bromide are added dropwise with stirring at boiling point and the reaction mixture is refluxed for several hours. Thereafter it is concentrated by evaporation. The product, bis-(thiomorpholinyl)-ethane-( 1,2), separates in the form of colorless crystals which melt at 97 to 98 C. Yield 36g.

STAGE ll Thirty-three g. of a polyethylene bistosylate which has an average molecular weight of about 1350 and 6.9 g. of the above bis-(thiomorpholinyl)-ethane-(1,2) are heated under reflux for 3 hours with 50 ml. of butanol. After evaporation of the solvent, compound II is obtained as a brownish waxy substance. Yield 38 g.

The substances according to the invention may be added to the photographic emulsion at any stage of its preparation before, during or after chemical ripening. They may also be added to the casting solution immediately before casting. The quantity added depends on the desired effect and can easily be determined by the expert by the usual tests. Quantities of 0.1 to 10 g. per mol of silver halide will normally be sufficient.

The emulsions can also be optically sensitized with cyanine dyes such as basic or acid carbocyanines, cyanine dyes of the betaine type, rhodacyanine or merocyanine dyes, styryl or oxonol dyes. Suitable sensitizers are described by F. M. Hamer The Cyanine Dyes and related Compounds. lnterscience Publishers, (1964).

The emulsions may also contain chemical sensitizers, e.g. reducing agents such as stannous salts, polyamines such as diethyltriamine or aminomethane sulfinic acids or derivatives thereof such as described in Belgian patent specification No. 547,323 or sulfur compounds as described in U.S. Pat. No 1,574,944, for example allyl thiocyanate, allylthiourea, sodiumsulfate and the like. Suitable chemical sensitizers are also salts of noble metals such as ruthenium, rhodium, palladium, iridium, platinum or gold, as described in the article by R. Koslowsky, Z, wiss.phot. 46, 65 72 (I959). Further suitable for chemical sensitization are polyalkylene oxides, especially polyethylene oxide having an average molecular weight of 1,000 to 20,000 and derivatives thereof, such as condensation products of alkylene oxides with aliphatic alcohols, glycols cyclic dehydration products of hexitoles, alkyl substituted phenols, aliphatic carboxylic acids, aliphatic amines, diamines or amides. The said condensation products have preferably a molecular weight of above 1,000. It is also possible to apply combinations of several chemical sensitizers. 1

Particular suitable for the emulsion of the present invention are chemical sensitizers of the thiomorpholine series such as described in French Pat. No. 1,506,230.

The emulsions according to the invention may additionally contain the usual stabilizers, e.g. homopolar or salt-type compounds of mercury with aromatic or heterocyclic rings, such as mercaptotriazoles, simple mercury salts, sulfonium mercury double salts, and other mercury compounds. Other stabilizers which may be used include azaindenes, especially tetraazaindenes or pentaazaindenes, in particular those substituted with hydroxyl or amino groups. Compounds of this type have been described in the article by Birr, Z. wiss.phot. 47, 2-58 1952). Other suitable stabilizers include heterocyclic mercapto compounds, e.g. l-phenyl-5-mercapto-tetrazole, quaternary benzthiazole derivatives and benztriazoles.

The emulsions may be hardened in the usual manner, for example, with formaldehyde or halogen-substituted aldehydes that contain a carboxyl group, e.g. mucobromic acid, diketones, methanesulfonic acid esters and dialdehydes.

The substances described may also be added to the developer, although they are less effective when used in this way. Amounts of l to 20 g. per. 1. of the aqueous developing composition have proved sufficient.

EXAMPLE 1 A mixed emulsion composed of 90 percent of a silver iodobromide gelatine emulsion and percent of a silver iodochlorobromide gelatine emulsion, which mixed emulsion has been ripened to optimum sensitivity in known manner with gold compounds and sulfur compounds is sensitized by the addition of 45 mg. of the following sensitizing dye per kg. of emulsion:

In addition, the following ingredients are added per kg. of emulsion:

g. of l-(3'-sulfo-4-phenoxy)-phenyl-3-heptadecylpyrazolone as magenta coupler, 250 mg. of l,3,3a,7-tetraaza4-hydroxy-6-methylindene as stabilizer, ml: ofa 5 percent aqueous solution of saponin as wetting agent, 2,5 ml. of a 30 percent aqueous solution of formaldehyde as hardener. The emulsion is divided into 10 parts and the following substances per kg. of emulsion are added to the individual parts:

Sample A: Comparison sample without additive. Sample B: 300 mg. of ofSubstance 1. Sample C: 300 mg. of Substance 111. Sample D: 1 g. ofSubstance IV. Sample E: 300 mg. of Substance V. Sample F: 300 mg. of Substance VI. Sample G: 300 mg. ofSubstance VII. Sample H: 300 mg. of Substance VII of British Pat. specification No. 1,145,186 of the following formula:

LNEC-CHzCHz-O-CHzCHz Sample I: 300 mg. of Substance No. XIII of British Pat. specification No. 1,145,186 ofthe following formula:

Color development 7 minutes Short stop bath 5 minutes washing 5 minutes Bleaching bath 5 minutes 5 Washing 5 minutes Fixing bath 5 minutes Washing 10 minutes The color developer has the following composition:

The other treatment baths had the following composition:

short stop bath: sodium acetate 30.0 g. Glacial acetic acid 6.0 g.

Make up with water to l l. Bleaching bath- Potassium ferricyanide 100 5. Potassium bromide 20 g. Disodium phosphate 10 g. Glacial acetic acid 4 g, Make up with water to l l: Fixing bath: Sodium thiosulfate 200 Make u with water to l l 5 The color density of the magenta layers was determined with a 3 Macbeth Quanta Log, Model TD 102" densitometer, a green color filter being interposed in the path of the beam of measuring light.

TABLE I Sample Sensitivity y Fog A Standard 0.6 .15 B +$.2 0.66 0.028 c +3.9" 0.61 0.24 D +4.2" 0.67 0.23 E +3.5" 0.67 0.26 F +3.7 0.66 0.23 o +4.| 0.69 0.24 H +i.7 0,67 0.26 l +1.8 0.68 0.27 K +2.1 0.70 0,30

3 denote a difference ofone shutter stop.

EXAMPLE 2 To the emulsion described in example 1 are added an optical sensitizer for the red region of the spectrum (40 mg./kg.) of the formula:

and the cyan coupler of the following formula:

The other additives are the same as those given in example 1. The emulsion is divided into 1 1 parts and the following substances per kg. of emulsion are added to the individual parts:

Sample A: Comparison sample without additive.

Sample 18: 300 mg. of Substance 11.

Sample C: 300 mg. of Substance 111.

Sample D: l g. of Substance IV.

Sample E: 300 mg. of Substance V.

Sample F: 300 mg. of Substance V1.

Sample G: 300 mg. of Substance V11.

Sample 1-1: 300 mg. of Substance V111.

Sample 1: as sample H of Example 1.

Sample K: as sample I of Example 1.

Sample L: as sample K of Example 1.

Subsequent working up is carried out as described in Example 1.

TABLE 2 Sample Sensitivity y Fogging A Standard 0,64 0.15 B +3.2 0.70 0,18 C +l,Z 0.78 022 D +2,4 0,68 0.19 E +2.9" 0.69 0.21 F +3,U 0.70 0.21 G +2,8 0,68 0,20 H +2.8 0,69 0,21

1 +1 ,2" 0,67 0,22 K +0,9 0,68 0,22 L +l,Z 0,70 0,26

3' denote a difference ofone shutter stop.

EXAMPLE 3 To the emulsion described in example 1 are added 15 g. of the yellow coupler of the following formula:

SOZH 1 C-CHr-C-NH NHC O-CnHas H3 without the addition of an optical sensitiserv The other additives are the same as in example 1. The emulsion is divided into 1 1 parts and the following substances are given per kg. of emulsion to the individual parts:

Sample A: Comparison sample without additive.

Sample B: 300 mg. of Substance 1.

Sample C: l g. ofSubstance 111.

Sample D: l g. of Substance 1V.

Sample E: 300 mg. ofSubstance V.

Sample F: 300 mg. of Substance V1.

Sample G: 300 mg. of Substance V11.

Sample 1-1: 300 mg. of Substance V111.

Sample 1: as in Example 2.

Sample K: as in Example 2.

Sample L: as in Example 2.

Subsequent working up is carried out as given in Example 1.

TABLE 3 Sample Sensitivity y Fogging A Standard 0.77 0.13 B +3,1- 0.00 0.20 10 c +3.2" 0.6! 0.20 o +3,1" 0.07 0.18 E +2J 0.06 0.20 F +2.8 0.66 0,20 0 +30 0,64 0,23 H +3,2 0.64 0.20 1 +1.7 0,00 0.23 K +1.5 0,62 0.21 L +1.9 0,66 0.29

3 denote a difference ofone shutter stop.

EXAMPLE 4 A silver iodobromide gelatine emulsion containing 0.25 mol. ofsilver bromide and 0.016 mol. ofsilver iodide per kg. is

used as basis for a multilayered color photographic negative material. The individual layers are optically sensitized as described in examples 1 and 2 (the blue sensitive top layer emulsion in this case does not contain an optical sensitizer) and the following color couplers are added:

1 kg. of the red sensitive emulsion of example 2 containing 20 g. of the cyan coupler l-hydroxy-N-octadecyl-2-naphthamide and the casting additives given in example 1 is applied onto a cellulose triacetat support.

On that layer is coated the green sensitive emulsion of example l which contains per kg. 16 g. of magenta coupler 1- (4'-phenoxy-3'-sulfo)-3-heptadecyl-pyrazolone-5 and the other casting additives given in example 1. A yellow filter layer of colloidal silver is cast on the green-sensitive layer. The

top layer consists of the nonsensitized emulsion of example 3 which contains 20 g. of yellow coupler 3-stearylaminobenzoyl- 3',5'-dicarboxyacetanilide and the other additives of example 1.

The above multilayer material is used as comparison sample (Sample A).

A second multilayer material (Sample B) was made in the same way but in addition contains 500 mg. of compound 11 per kg. of emulsion in each emulsion layer.

Samples A and B are exposed to white light behind a grey step wedge and developed for 8 minutes in a developer of the following composition:

N,N-Diethyl p-phenylenediamin sulfate-2,75 g.

Hydroxylamine sulfate-- 1 ,2 g.

Sodium carbonate anhydrous-2,0 g.

Sodium hexametaphosphate2,0 g.

Potassium carbonate anhydrous75,0 g.

Potassium bromide-2,5 g.

Water up to-- l ,000 ml.

The samples are furthermore processed as described in examples l to 3.

The results of the sensitometric tests are shown in table 4.

TABLE 4 Sample Sensitivity 7 Fog A yellow Standard 0,73 0,20

'70 Byellow +2 0,75 0,30

A magenta Standard 0,68 0,25 Bmagenta +2 0,70 0,27 A cyan Standard 0.75 0,18 B cyan +2 0.78 0,20

An increase by 3" corresponds to a sensitivity increase of one shutter stop.

EXAMPLE The example illustrates the comparative ineffectiveness of the substances according to the invention in a silver chloride emulsion which does not contain a color coupler. The following casting additives 5 ml. of a 1 percent aqueous solution of --phenyl-5-mercaptotetrazole as stabilizer,

2 g. ofsaponin as wetting agent, and

2 ml. of a l0 percent solution of formalin as hardener are added per kg. of a silver chloride gelatine emulsion which has a silver chloride content of g. per kg. of emulsion and which has been prepared in the usual manner.

The emulsion obtained in this way is divided into five parts and the following substances are added to each part:

Sample A: Comparison sample without additive.

Sample B: 300 mg. of Substance 1.

Sample C: 300 mg. of Substance ll.

Sample D: 300 mg. of Substance [11.

Sample E: 300 mg. of Substance V".

This casting solution is applied onto a baryta coated paper support, exposed behind a grey step wedge and developed at C. for 1 minute in a developer of the following composition:

Water-750 ml.

p-methylaminophenol-l g.

Sodium sulfite anhydrousl 3 g.

l-lydroquinone-3 g.

Soda anhydrous26 g.

Potassium bromide-l g.

Water up tol .000 ml.

TABLE 5 Sample Sensitivity 'y Fog A Standard 2.74 0.06 B :0 2.74 0.06 C +0 I 2.75 0.06 D :0 2.72 0.06 E +0 2.74 0.06

A difference ol'3.0 corresponds to a sensitivity difference ofone shutter stop.

We claim:

1. A light-sensitive photographic material with at least silver halide emulsion layer which contains a color coupler capable of forming a dye upon reaction with the oxidation product ofa color-forming developer, the said silver halide emulsion layer is chemically sensitized by a water-soluble quaternization product of a aw-bis-(thiomorpholinyl)-alkane with a bifunctional polyalkylene oxide.

2. The light-sensitive photographic material of claim 1, wherein the silver halide emulsion layer contains a chemical sensitizer of the following formula:

wherein represents a=2 to 6, n=3 to 300, y=2 to 10, and x=an anion. 3. The light-sensitive photographic material of claim 2,

wherein represents a=2, n=23, y=3.4 and .r=tosyl.

4. The ight sensitive photographic material of claim 2,

e l N(CHi). cm-cH,- 21

wherein represents a=2 to 6.

y=2 to 10. and

x=an anion.

8. The process of claim 7, wherein represents a=2, "=23, y= 3.4 and x=tosyl.

9. The process of claim 7, wherein represents a=2, n=235. y=3.7 and x=tosyl.

10. The process of claim 7, wherein represents a=2, n=270, yflfl and r=tosyl. 

2. The light-sensitive photographic material of claim 1, wherein the silver halide emulsion layer contains a chemical sensitizer of the following formula:
 3. The light-sensitive photographic material of claim 2, wherein represents a 2, n 23, y 3.4 and x tosyl.
 4. The light sensitive photographic material of claim 2, wherein represents a 2, n 135, y 3.7 and x tosyl.
 5. The light-sensitive photographic material of claim 2, wherein represents a 2, n 270, y 4,8 and x tosyl.
 6. A process for the production of photographic color images by exposing and developing a photographic material with at least one silver halide emulsion layer which contains a color coupler, wherein the development is performed in the presence of a water-soluble quaternization products of an Alpha omega -bis-(thiomorpholinyl)-alkane with bifunctional polyalkylene oxide derivatives.
 7. The process of claim 6, wherein the quaternization product has the following formula:
 8. The process of claim 7, wherein represents a 2, n 23, y 3.4 and x tosyl.
 9. The process of claim 7, wherein represents a 2, n 235, y 3.7 and x tosyl.
 10. The process of claim 7, wherein represents a 2, n 270, y 4.8 and x tosyl. 